Abstract: In a yarn feeder used in a jacquard knitting machine, each yarn tension bracket includes a casing covered with a cover plate, a pivot shaft supported on bearings between the casing and the cover plate, a yarn tension rocker formed of two wire rods respectively fastened to two opposite round pins at two opposite ends of the pivot shaft outside the casing and the cover plate and turned with the pivot shaft to adjust the tension of yarns passing through upper and lower thread eyes at the wire rods, and an auxiliary yarn guide with upper and lower thread eyes fastened to the casing and the cover plate to guide two yarns passing through the upper and lower thread eyes at the yarn tension rocker and to prevent the yarns from being tangled.